How do I measure the diameter of a silicone tube?

When you place an order on silicone tubes with us, we define the measurements as follows:

The inside diameter of the tube/hole x a specific wall-thickness.

That is to say: an inside diameter of 10 mm x a wall-thickness of 2 mm thereby gives the tube a thickness of 10+2+2=14 mm (see drawing below).

Also read:

What is the difference/are the differences between PTFE and TEFLON? How do I tell the difference between silicone and rubber? How do I measure the hardness of the silicone? What happens when TEFLON gets too hot? Which temperatures can TEFLON endure? Which temperatures can silicone endure? What is the difference between low value and high value ohm? How do I measure the diameter of a silicone tube? Does the diameter of the silicone tube affect the thickness of the content when the content is extruded out of the tube? What happens when TEFLON gets too hot? (1)